Two-part breech closing mechanism for repeating firearms



A. A. DICKE TWO-PART BREECH CLOSING MECHANFSM Oct. 11, 1949.

FOR REPEATING FIREARMS 2 Sheets-Sheet l Filed Feb. 9, 1945 lll-I Ill: i. .1. .l

Il 2M. I

JNVENTOR ALLEN A DICKE u C. )lip/16' ATTORNEY A. A. DICKE TWO-PART BREECH CLOSING MECHANISM Oct. 1l, 1949.

FOR REPEATING FIREARMS 2 Sheets-Sheet 2 Filed Feb. 9, 1945 INVENTOR. 4L/.EN A. DlCKE TTORNEY Patented Oct. 11, 1949 PAIE ENTI? QF-FICE;v

TW OV-IHIVIBREECH` CLO SIN G'MECHNISM i FOR REPEATING FIRERMS AllenfA. Dicke,,U'pper Montclaii';,N .v J .14

iipliationFebruary, 194`5`,'^`Srial' Nb. 5713967" 3- Claims.,r v (Cl. 421,-18 )a 13;* zit Thisinventlonrreites'to"iinprovements'in remeans' for* such ffafgunl comprising a hand lever peafting'rearmsgand'has foranobliect toprovide" pivoted'et itsupp'er-and forward end to the bolt an improved "rrary"v boit earrn" construction; carrier"'zmd"-pivotedi at aninter-mediate pointto' mostofth'e parts ofwlii'ch maybe-utilized ini such a-'isupporti'ng linie-Which is'inturnpivoted= to thet guns .Whether` the' repeating. operation' is effected` 5 receiver, whereby movementfoffsaid'lever'and link by'4 aiever actionW device, ersiiding4 foreeend, or isfsuchthat' thepivoted/forward end` of the-opjs` of the Straightgpunfconstruction; erating`A lever may` move' rectiiineariy, as en Anotherobj'ect is" to"provide^improved' guns'irrV forced by the path of movement of the Vbolt carwhichrtne breechis ciosedrby-means-for :i` bolt ner,y and-whereby powerful lveraeemay be aphaving; oneformorevlocking" 'lugspreferab'ly-near' 1o plied:tothebolt'carrierfduringltheearly partei` its frontend", Wiichboitiis"helieaily` connectecr- S mOVeHlei: While-unlocking and extraction to"a"bo1t"cani'er', ,which *is* slideyrnounted in a occurs.

receiver. Another :obj ect i is Lto provide a bolt carrier, the Anotherobjects-'to-provide suchfan arrange; rear endioffwhioh -i'slocatedforwardly of the rearmentnwhichvthevrotative position ofthe boit 15 of the cartridge magazine;`r sofas to-permit of a.r isdenitelyicontroied'" inali parts of; the` excur` corresponding Sheltenig'ofthereceiver; together sion of the-bo1t"carrier:' with the provision of means for keeping closed"A Anotherolcjeetiisrtoirprovidesuch1 a*- construc'- that' portion ofithelejectionfoperngheated real"- tion-inwhichthe-helical` connection-is formed; Wardly of the o oltarrier. means of'lgeneraii'yheliealfopposed slots'irrthr-y'20 Another? obseetis` t0' provide mpaet lrlg shank-orthe-bolt throughi which siotspasses themechanisme'capabievoextendne above the 110ppin mounted^"in`--the Holt-carrier; the slot being" most cartridge in the magazine and reaching for soformedasetaprovideva,@"dwellmin `than: portion Wardftovti'ei-rear-endrothe* ring pin at a, point thereofa-di'acent the'pinfwhen'the breech-mechi` intermeditef-'thehends'f of said itopmost cartridge. anism"is"c1osed," sortira-t rearward-thrust Whicir- 25 A more specic objeetisito provide for this pur mightresuit* from ex'cessiveheadl space isH inca pose=an=iinpactiingmechanism having an impable voffimpzntiiig rearward* motion te thebolt' pab'fmember capable-affamalmovement. together carrier. with a compressionspringr therefor iocated in a;

Another'oHj-ectisto provide-"such-'a' construo-n tubular hmslglwheh VIllty Conveniently Serve tioninwhich*aeartrideeXtrafctor 'is carried-BT 30 aS'i'I-'aielng IJOIll'fOr a Steekibolt. the bol-t itselreandfisflocatedbetweenaf lug there Anotherobiect isrtofprovide.: an. improved aron and 'saidrspiraisiot soeth'atthe-extractormayrilrgemet.fondeteheibly eemletng Such all? extendsubstantiallythe=fent^iref1ength ofthelbow; operating-levert@ theublticarrer; Said conne@` being attached theretoneafrtheerear end ofthe tinmbeillg:acceSSbeJN/henthebolt Carrier iS in tSf boit. 35 extreme rearward positionrsorthatsthe bolt carrier Another olojectfiis` to-providesn'chi` er.y device inf andsxboltmayfbezwithdrawn rearwardly from the;` Which=the -bo1t ca-rrieris formed with:l oneworAl Slm. u morel outvvardiy"rex-tenditigkeysi which` are'A s1id ilnothersobject is tonprovideraniimproved firing:v ablyT receivedlinf-corresponding guidel grooves-inf pin constnucte'dfonsuenasgurntwhich pin is pro.-

thenteriorof'f'thereceiver; and the"spireti slot' 40 videdfiwith elongatedopening-through. which: tYiebOItshanIfSL'Se located-thatftheecrosslpin is', maymass thepinszcarriedlbyfthevholt carrier andt in lineU with the' Iugs=on= the boitlwiienithefbolt'ls passing through the spiral slots in the bolt shank,A

rotatedto itsfuniocked position'fsolthoyt-theopen'- whereby "thiexrmgzzpim iszxheldragainst excessive ings in the'bolt-carrier receive thecrosspina: rearwardzmovementiand, is-.vretracted from thef may beslocatedlwithin'the keys-on the bolt murieray 45 cattridgezatth'e zsttpartofzthe rear movement; orf` forward@V extensionsathene()f..y of 1 the: bolt carrier.

Anotherobi'ect ist@ provide'improved 'ejectorfff An'otl'ien:objeet isatoxprovdeisuch aegun oper-- Inec};\a-r11ism1 A comprisingaaneejectingfpin slitlabiyl ated bylmeansiof'a:sliebleforeqend and an action' mountedginttnewrotamyfbnltg. togettfenwith afpni barrconnectedtherewithnnd;also toz'the bolt cau:L for operatingsaid; ejectorfcarriedoynthefreeeiverz: 50 renbvmeanso conveniently detachable means. theclosure; `or lotherstaiti'onary fdevicesaidriasn@ Anot'hermbiect is-:toziprovidefsuch a. gun of the'r mentionedf pinbeingvsovlooated that'vit may passi straightepuil; type(bytproviding,aidetachable oper'- throughiamzapentureeinatheaboltr-.oamri'em ineline. azting knob, wconnectedxtoxthe. boltfcarrier prefer-- with the:rotativeipositionaoizthe'ejector rpimwl'ierr` abbe at; thatpart thereofeto, the rear of lthe' boltv thevloeit;iseininiusxiockied;posiiziiorm4 n 55 shoznkcn Another:obect intaprovidesirmaroveliloperating` Another object is to provide an improvedboitli g lug abutment collar which is formed separately from the receiver and the barrel so that accurate abutment surfaces may be generated thereon to assure close mating engagement between the rear lug faces and the forwardly facing abutment faces, and likewise between the forward lug faces and the rearwardly facing abutment faces in such abutment collar.

Another object is to provide such an abutment collar and mating surfaces on the bolt lug-s of helical conformation so that the bolt is moved slightly rearwardly during its unlockingmovement to provide a powerful primary extraction, and to provide also a powerful cartridge seating movement.

Further objects and advantagesA of this invention will be apparent from consideration of the specification as illustrated bythe accompanying drawings of possible embodiments of the invention, in which drawings:

Fig. l is a vertical, substantially medial, crosssectional view of a rifle intended for powerful bottle-necked cartridges, such as the 30-06. caliber Springfield cartridge, the operating mechanism being of the lever type,

. Figs. 2, 3, and 4 are cross-sectional views taken along the lines 2 2, 3 3, and 4 4 of Fig. l, respectiVely, l

Fig. 5 is a cross-sectional View, partly fragmentary, taken substantially along the line 4 4 but looking rearwardly, the breech mechanism being in its extreme rearward position,

Fig. 6 is a fragmentary cross-sectional view taken along the line 6 6v of Fig. 5, looking in the direction of the arrows,

Fig. 7 is a perspective view of the lug abutment collar, v

Fig. 8 is a perspective view of the bolt carrier shown in Figs. 1 to 6, inclusive,

Fig. 9 is a perspective View of the bolt,

Fig. 9A is a perspective View of a shield for the ejection port,

Fig. 10 is a fragmentary side elevation, as viewed from the left, of a gun of the same type adapted for fore-end operation,

Fig. 11 is a fragmentary side elevation, as viewed from the right, of a gun of the same type adapted for straight-pull operation,

Fig. l2 is a plan view of the gun of Fig. 11.

Referring primarily to Figs. 1 to 9, inclusive, the numeral 2l indicates a barrel of more or less usual construction formed with a chamber adapted to receive a cartridge 22, The barrel is attached to a receiver 23 by any suitable means, such as screw threads 24. The receiver has secured to it a stock 25 of wood or the like which may extend forwardly to provide the fore-end 25a and to enclose the lower part of the sides of the receiver. However, in the form shown in Fig. 10 the stock 25 terminates at the rear end of the re.- ceiver, which is entirely exposed, as is usual in sporting ries.

The receiver is generally hollow, being formed with a bore 26 corresponding generally to the desired diameter of the bolt carrier 21 from a point at its rear open end to the forward end of the bolt carrier when the latter is in its extreme forward position. The bolt carrier 21 is formed with two guides or keys 2'.'aI and 2lb, and the receiver is formed with corresponding guideways 28a and.

28D, so that the bolt carrier is free to slide axially within the receiver but is prevented from rotating therein. As shown in Fig. 8, these keys are provided with forward extensions 21a and 2lb', respectively, for a purpose to be described later.

The bolt carrier is formed at its forward end with a cylindrical bore 29 extending about twothirds the length of the bolt carrier and serving to receive the shank portion 30a of a bolt 30", the forward end of which is provided with locking lugs 30er and 3Ghz. The shank of the bolt is provided with generally helical slots 3001 and 3002. The bolt is connected to the carrier by means of a pin 3 l which preferably extends'entirely through the bolt carrier and bolt, as shown. The generally helical slots are so located that their rearward ends are in line with the lugs 3llb1 and Sbz. This v is desirable because it causes the lugs to be in line with the guide grooves 28a. and 28h so that they may be guided thereby during the rearward excursion of the bol/t. This prevents unwanted rotation of the bolt."l VBy having the helical slot located as described, the cross pin 3l may be located in alignment with the guide ribs 21a and 2lb of the bolt carrier, being supported in holes 3| therein (see Fig. 8). This provides a stronger support for the pinv 3l and permits making the balance of the walls of the bolt'carrier thinner than would otherwise be the case,

In the form shown the bolt is rotated about 69 between its locked and unlocked positions. The lugs are substantially vertical in the locked position and are at an angle of about 30 from theA horizontal in their unlocked position (see Fig.5)

This makes a desirable arrangement since the extractor of the construction shown must be located between the lugs and must, at the same time, be so located that the ejection opening will be in a satisfactory location. This is made possible by the arrangement shown, as the ejection opening be made relatively long and springy if desired.,

The extractor has a claw 32a which normally `overlies the rim of the chambered cartridge and a shank portion 32h, the rear end of which is formed with a transverse dovetail 32o fitting in a corresponding slot in the bolt shank. The shank 32h of the extractor lies in a clearance slot in the bolt. Its external dimensions are such that clearance is provided to permit the extra-ctor claw to pass over the cartridge into the extraction groove, and the extractor shank is made sufficiently thin and springy to permit this action.

The forward and rear faces of the locking lugs 30b1 and 30192 are preferably made as helical surfaces of quite low pitch so that thehelix angle is considerably smaller than the angle of repose. This construction provides a powerful primary extraction, since a comparatively small axial movement is enforced as a result of a rotary movement of some 60. Furthermore, the lead of the helical slots 3001 and 30c2 is comparatively great so that the rearward force applied to the bolt carrier provides a rearward extractive pull on the cartridge case many times said force. Furthermore, the rearward force applicable to the bolt carrier is multiplied greatly during the preliminary part of its movement by the lever operating mechanism to be described later. It will also be noted that the extractor rotates with the' rotating bolt during the time of primary extraction so that a torque is applied to the cartridge case, tending to twist the case out of the chamber, and thereby facilitating'the original, occasionally difficult, part of the extraction. Since the extractor agencer.:

lie's*-in"-al` groove in the" bolt itI is Well supportedi'l against peripheral movement and, therefore;` is` well capable of applying such an extractiva twist tithe cartridge case.

The rear par-t of'the receiverA bore is shown cl'os'ed byV 4aclosure plug 33giwhich' has a generally cylindrical. forward portion Afitting into the bore 26 Aand Vis provided* with'` lugs 33a.' capableV of being.l seated'iin correspondingi recessesin the receiver body.-` Inorder `to removethe closurait is'twisted? tothe required extentand.thenwithdrawn aXiallyL ofJthe'bore; that vportionof theireceiver being pre-e ferablylformedas shown' at 23a to-permit such'removal;

In order to provide for aY satisfactory ejection ofthefiired cartridge casathe bolt may be formed aseshown with abore parallel with itsV axis arranged diametrically' opposite the extractor (see- Figf. withinfwhich is housed an ejector pin 34, preferably'held in place by a pin 3fm carried by the bolt and receivedin part in a slot 34h in the ejector pin V(Fig. 6). An ejector operatingpin'Sllc is-carr-ied by the closure 33 insuch a position that when the bolt isy rotatedto unlocked position it aligns withthe ejector pin 34, therefore as the bolt` carrier approaches the rearward limit of its excursion (as shown in Fig. 6)', the ejector operating.. pin 34o passes through an opening 34d in the bolt carrier andits front end stops the movement of ejector pin 3`4`, causing its forward end to throw the cartridge case out of the receiver in a direction upwardly and to the right, as viewed from the shooters position.

Firing pin 35 may consist'of a shank portion 35d; an enlarged central portion 35h, a forward shankportion 35o, and a striker part 35d which isin linewith a small' opening 36d' in the forward end of thebolt. Thering pin is formed `with an elongated opening 35e, through which the cross' plh 3| normally passes. Thus the cross pin not only 'serves to hold the firing 'pin' against execs-- sive rearward movement, butdraws the firing pin Y rearwardly away from the cartridgeas soon as the boltcarrier moves rearwardly. Furthermore, itpreventsY the firing pin from reaching the cartridge until the action is-fully closed. To accom plishthe latter'purp'osathe helical slots Eecran'd h11"are.eachformedwith a dwell portion 343cm; (Fig. 9) and 30cm (shown in dotted lines in Fig. 1) attheir forward end..` It will be seen further that the bolt will have been completely rotated to locked` pcsition before-the bolt carrier is fully forward,so that the crosspin 3l holds the iiring pinf away-'froml the cartridge until after thebolt carrier isifgiven an additional forward movement. This dwell construction-hasthe further advantage that rearwardthrust of .the bolt at the momentv of.-firing, which might occur if excessive head spaoeis present, is not capable of applying a rearthrust to the cross pin and, therefore, to` the bolt carrier-which might, under certain conditions, cause the gun toshoot open, particularly` the straight-pull modication toY be described later.

It will be noted from Fig. 6 that the enlarged' central portion h of the ringpin is formed with' agroove'to receive the rear portion ofthe ejector'` pin '341 It will be noted that the rear end of the'bolt carrier does not reach to the rear limit of the cartridge magazine and the ejector port, which is'designated 3B (see Figs. 1, 3, 11, and 12). In' this way it is possible to shorteny the' receiver and therefore to reduce the rlength of the entirearm. This,` however, leaves" a'nopening com` prisi'n'g thatSpar-t or theiejectionport totherear: of'ltheflm'lt` carrier; This would be v unsightly and.' would permit` the'entry or dirt,` twigs, leaves, eter which mi'gh'tinterfere-fwithl the= functioning'offl L thearm.- Means are: provided to close this openwing'whi'ch, at the 'sameltima are so arranged asl; not to prevent?thebolticarrier from moving all. the-Wayback intofen'gagement with the receiver". closure1'cap=33 'Ilh'ese` means inthe form showna 'comprisea cylindricalfshield'i (Figs. 1, 4, 5, 6,.9a.,.

115,! and'lZ); 'Ifhe internal radius ofsuch shield' may preferably correspond `to the external-radius: orth'eA bolt-carrier 217.. It is, however, provided itsforwardendlfwith an inwardly extending? r flangeS/'ia (shown in-dotted lines nligs. 4 and5,.

andi-inl crossfsectionin Eig. 6Min perspective ina' ,Y

Fig.' 9d; and in full in Fig. 10). This flange rides'.r upona attenedvportion 21cformed at thegtop.` ofthebolt carrier' 215 (see Figs. 1, 3, 8, and 10). The external radiusiis siightly greater andthe* thickness of materialfis accommodated byia cor-- responding cut 31'1'c inithe interior of the receiven (Figs. 1 and). This Jcut is also made suilcientlyVV deeptol accommodate ani outwardly extending.:

ila-nge 3'lbfformedonl the shield. It will be seem.

therefore, that when theA breech mechanism isf inciosed position the shiei'dlwill be drawn. intor the positionfshowninFigs. .1, 10, 11, and 12,' but: that when the action.l is-iully` open the shield 31fwill be pushedbackwardly to the position shown in Fig. 6;' this' resulting from the engage-- ment of vthe forward? end-.offcut-away portion 2"lc. on the bolt-carrier withlthe forward edge ofthe' flange;` 31a-onf the" shield' 3.1; This. mechanism;

' providesI a simple', cheapilrfoolproof arrangement` inclosing the openingreferred to and makes;V` possible the shortening of- `the receiver'and, there'= fore; the shorteningof the arm as a whole.

The re'aren'd of the'ring pin 35 must necessaril'yterminate at-apoint forwardly of the rearf ofthe base of the cartridges in the magazine and: the hammer 'must beso arranged that it normallyi 1iesto the rear of the magazine but must be! able' to reachfupwardly andi forwardly to striker ftle ring pin.^ Thisfmay be accomplished by a7 pivoted hammer with' a forwardly extending nosei butitis preferred to-use the form of construction shownr in Fig. 1. Tli'erein the hammer com` prisesl 'af-longitudinallyslidable rod 40, preferably.- sl'idably m'ountedlin a tube 4l inclined at an angle,` as shown. Within saidA tube to the rear of the: hammer is shown a coil spring 42 shown as*` housed in part in a tube 43 in line with tube 4I.. These tubesr are shown supported by being y threaded into an 4extension 23h ofthe receiver 23,.

which also has arearward extension 23e tting. againstithe stock 25-andsecured thereto by means ofy screw 23d. The. tube. i3 may conveniently serveas a connecting, point for a stock bolt 44' passing through to the butt of the stock. The hammer is provided with a sear notch a receiving they hookof a sear 45 operated at willA by a trigger 46, which is shown as formed integral with the sear, the sear trigger memberl i being pivoted at 41 and biased counter clockwise by any suitable spring (not shown). It will-` be readily understood that with the hammer in' the position shown in Fig. 1 when the trigger ispulled the hammer will be released and will be urged forwardly and upwardly by spring 4? until it strikes the rear end of ring pin 35 (dotted line position). This drives the firing pin forwardly causing its end 35d to strike and explodei the-primer' of the: cartridge 22. When thereafter 'is the-:aetion-is openedby drawing thebolt carrier:

21 rearwardly, the lhammerv 40 is forced rear-l wardly and downwardly by the firing pin and then by the rear face of the bolt carrier until it assumes substantially the position shown in full lines where its forward end has escaped below the bottom of the bolt carrier so that the bolt carrier may continue its rearward movement until it engages or substantially engages the closure cap 33. In the meantime the hook of the sear 45 is engaged in the sear notch and thus holds the hammer in retracted position ready for ring the next shot.

The bolt lugs 30191 and 30132 may inter-engage with locking abutment surfaces formed integral with the receiver, in accordance with common practice. However, the present invention contemplates the provision of a separate member for this purpose. Said member may take the form of abutment collar 48 shown in perspective in Fig. 7. This consists of a continuous ring portion 48a and bifurcated rearwardly extending members formed by two longitudinal slots 48h into which the bolt lugs may pass when they are in unlocked position (Fig. Y) and generally circumferentially extending recesses 48C within which the bolt lugs are received when the bolt has been turned to locking position (vertical in the form shown). In order to secure firm seating of the cartridge in the chamber and particularly to provide primary extraction, the surfaces deflned by the recesses 48e preferably extend helically. This helix is of such small advance per turn that the angle is considerably smaller than the angle of repose so that no amount of thrust against the bolt face will cause the bolt to turn to unlocked position. The parts are so dimensioned that the lugs, which have correspondingly-formed helical forward and rearward faces, lt rather closely in the recesses 48o. Therefore, as the bolt is rotated toward locking position it is screwed forwardly to seat the cartridge in the chamber and when rotated to unlocking position the bolt is screwed rearwardly. This will be suiicient to cause primary extraction, i. e., to cause the extractor to loosen the fired case from the chamber.

The abutment collar 48 is located in a counter bore in the receiver (Fig. 1) with its forward continuous section 48a surrounding a reduced extension 2id on the barrel. This is preferably fitted quite closely so that the ring 48a will serve to strengthen the -chamber against the explosion pressure.

The advantage of forming the lug-engaging surfaces in a separate member, such as 48, is that it is difficult or impossible to generate properly formed surfaces of this type within the receiver. When made as shown in Fig. 7, the surfaces may be generated accurately on a milling machine by using end mills or a slotting attachment. Such a helical surface is the only one whereby relative rotation will produce corresponding relative axial movement while maintaining full surface contact. This assures proper seating of the cartridge, minimum head-space, and easy extraction.

The arms shown as illustrative of the invention are of the box magazine type, i. e., extra rounds 22a are stored in a box magazine below the bolt carrier, these rounds being urged upwardly by means of a follower 22h of the usual construction urged upwardly by means of a spring of usual construction (not shown). To facilitate transfer of the topmost round to the chamber, a,

bullet incline 23e is formed forward of the top-m' most round.

Means for operating the breech action by moving the bolt carrier 21 first rearwardly and then forwardly will now be described, attention being nrst directed to the lever operating deviceA shown in Figs. l to 5, inclusive. The lower left erably provided with a rearwardly extending pin 52h located in a slot in the rear of the bolt carrier Said pin is for the purpose ofV moving the pvot pin 52 toward the right for disconnecting the arm 5 la from the bolt carrier when it is desired to remove the bolt carrier and (Figs. 3 and 4).

associated parts from the receiver.

The operating lever 5l includes also a trigger" guard portion Ellay and a finger loop 5Ic in the usual manner.

secured thereto.

By means of this construction a powerful leverage is assured during the early part of the movement of the bolt carrier since when the lever 5l is started downwardly it swings about hinge 55. Since this hinge is only a short distance below the bolt carrier (measured perpendicularly to the line of motion of pin 52) a force multiplication of about 6 to 1 is attained. This applies a powerful rotative effort (torque) to the bolt, due to the high lead of the cam slots 30er and 3G02. This high torque acting through the small lead helix, on the bolt lug faces and their mating surfaces in the member 48 provides an extremely powerful primary extraction.

Unlocking action of the bolt takes place during the comparatively long movement of lever 5l from the full line position to the first dotted line position, during which the most important During this time the link 54 moves i from the full line position to its dotted line posiwork is done.

tion. Continued movement of lever 5l from the first dotted line position to the second dotted line position causes the link 54 to move upwardly.` until it resumes its original (full line) position.'

The bolt carrier has now achieved its rearmost position where it engages the closure lug 33.'

During the last part of this motion ejection occurs through the means shown in Figs. 1, 5, and 6, as described hereinabove.

the bolt face, which is now in the position shown in Fig. 6. its first dotted line position will cause the bolt carrier and bolt to move forwardly to the position where the cartridge is substantially fully` seated in the chamber. Further movement of lever 5l to the full line position serves merely to rotate the bolt to locking position. During` this time the bolt moves forward only that slight distance which is caused by the coaction of the helical surfaces on the bolt lug faces and the corresponding surfaces on the abutment collar 48. This movement causes the cartridge to be firmly seated in the chamber. This lever arrangement permits the use of a swinging lever to The operating lever 5I is shown hinged at 53 to a link 54, the forward end of which is hinged as at 55 to the receiver or some member At this time the topmost round has jumped upwardly, as is common in guns of this type, to a position ahead of Return movement of the lever 5I tol apply rectilinear motioni 'tol a breechclosiig Fmemberwith 4a poweriulleve'ragei and by means cf-3a construction. which permit'sthe useY oft are- `cel/'er1' dif-proper height,- an'dk permits? the con- Astructi'onl of agun cfA this type with pleasing 'fllnesfarid without undulylar-ge dimensions `at fthe receiver. rEhe lever 5| is also preferably formed' witha slot ciosing shield 5rd; ofsegmentaltor-m lying inthe planeet arm 5 la'.y This lfi's`- used only if the arm v51u` is`I so formed that linz-extracting position-of lever 5lit willpass*l into the' space in frontofthe trigger- Lit. Ii* that-occurs a corresponding slot must be formed in the receiver, which slot will be normally closed by the shield id.

While the above-described means serve admirably to provide an excellent bolt-action leveroperated high-power firearm, many of the parts may be used or readily adapted to make an excellent slide-operated, bolt-action arm. Such an arm is shown in Fig. 10. In this case the receiver 23 is preferably not covered by the stock, which terminates near the rear end of the receiver. The breech-closing action is operated in this gun by means of a sliding fore-end 6!) supported under the barrel 2l by any suitable means, such as a dovetail, and which serves to operate an action bar 60a, which passes through a correspondinglyshaped recess in the front of the receiver and is formed with an upwardly-extending arm 60h,

which is perforated to receive the pin 52, described above in connection with the lever-operated gun.

The operation of this slide-operated arm is similar to that of the lever operated arm. After ring the fore-end 6D is drawn rearwardly by the shooter. This, through bar 60a, arm Elib, and cross pin 52, causes the bolt carrier 21 to be retracted. During this motion cross pin 3| operates in helical cam slots Bcl and 3002 to rotate the bolt from locked to unlocked position. During this unlocking movement primary extraction takes place. Further rearward movement causes the completion of the extraction, ejection, and cooking of the hammer. Forward movement of fore-end 60 causes transfer of the topmost round from the magazine to the chamber and rotation of the bolt to locked position. To disassemble a gun of this form the fore-end E!) is merely drawn back to its extreme rearward position, the receiver cap 33 is removed and the user can then reach pin 52h (Figs. 3 and fl) and thereby move pin 52 to the right, disconnecting it from action bar 65a. The bolt carrier with the firing pin, bolt, and extractor can thereupon be moved rearwardly out of the receiver. This also permits cleaning of the barrel from the rear.

Similarly an excellent straight-pull bolt-operated gun may -be provided by utilizing or adapting most of the parts described. In this case the bolt carrier is provided with an operating handle or knob t5, the inner end of which is detachably connected with the bolt carrier 2l as by screw threads or other means. This operating knob is preferably so located that it is attached to the rear part of the bolt carrier where the carrier is substantially solid and, therefore, supplies proper connection means for the operating knob. 'I'he receiver in this case is formed with a clearance slot EE, within which the shank of knob 65 may move during reloading operations. To disassemble, the knob t5 is drawn rearwardly to partly or fully open the action. The receiver closure 33 is removed, the knob 55 is disconnected, andthe damen" and -bolti'are'ipushedrearwardly out of the ftion `and-not as limiting as-v-arious modifications itlierem may be made without departing the invention as defined by a proper interpretation of the claims which follow.

I claim:

l. In a breech-loading iirearm, in combination, a receiver provided with two diametrically opposed bolt-lug engaging abutment faces; a breech closing mechanism comprising a non-rotary bolt carrier and a rotary bolt formed with two diametrically opposed locking lugs, helically connected to said carrier, the said bolt carrier and bolt being reciprocable within said receiver from a rearward position to a forward position where the bolt has been rotated to locked position by said helical connection, the bolt carrier being formed with two diametrically oppositely extending guide projections, corresponding guide recesses formed in the receiver within which said projections t, whereby the carrier is held against rotation, the lugs on the bolt being so arranged that they align with and extend into said guide recesses when the bolt is in unlocked position so that the bolt is held against rotation during the reciprocation of the bolt within the receiver, said helical connection comprising a pin carried by the bolt carrier within and extending through the said guide projections.

2. In a breech-loading firearm, in combination, a receiver provided with at least one bolt-lug engaging abutment face; a breech closingmechanism comprising a non-rotary bolt carrier and a rotary bolt formed with at least one locking lug, helically connected to said carrier, the said bolt carrier and bolt being reciprocable within said receiver from a rearward position to a forward position where the bolt has been rotated to locked position by said helical connection, the bolt carrier being formed with an outwardly extending guide projection, a corresponding guide recess formed in the receiver within which said projection ts, whereby the carrier is held against rotation, the lug on the bolt being so arranged that it aligns with and extends into said guide recess when the bolt is in unlocked position so that the bolt is held against rotation during the reciprocation of the bolt within the receiver, said helical connection comprising a pin carried by the bolt carrier within and extending through the said guide projection.

3. In a breech-loading rearm, in combination, a receiver provided with at least one bolt-lug engaging abutment face; a breech closing mechanism comprising a non-rotary bolt carrier and a rotary bolt formed with at least one locking lug, helically connected to said carrier, the said bolt carrier and bolt being reciprocable within said receiver from a rearward position to a forward position where the bolt has been rotated to locked position by said helical connection, the bolt carrier being formed with an outwardly extending guide projection, a corresponding guide recess formed in the receiver within which said proj ection ts, whereby the carrier is held against rotation, Said helical connection comprising a pin carriedwby the bolt carrierwithin and extending Number through the said guide projection. 659,786 ALLEN A. DICKE. 853,438 966,482 REFERENCES CITED 1,096,324 The following references are of record in the 1,322,438 file of this patent: UNITED STATES PATENTS 21125571 Number Name Date 10 2,364,548 398,064 Mauser Feb. 19, 1889 2,386,543 472,795 Mannlicher Apr. 12, 1892 2,424,264

12 Name Date Browning Oct. 16, 1900 Browning May 14, 1907 Slawter Aug. 9, 1910 Stamm May 12, 1914 Henderson Nov. 18, 1919 Dicke Mar. 31, 1936 Loomis July 6, 1937 Jacobson Aug. 2, 1938 Pedersen Dec. 5, 1944 Collins Oct. 9, 1945 Yorks July 22, 1947 

